Uniper to coordinate demolition of Swedish reactors

21 December 2018

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Uniper has drawn up a "long-term and common strategy" for the demolition of the two-unit Barsebäck nuclear power plant in Sweden, together with units 1 and 2 of the Oskarshamn plant. Decommissioning work is already under way at all four reactors.

The three-unit Oskarshamn plant (Image: Uniper)

The utility said the strategy is "intended to create logistical and economic coordination benefits between the two ongoing projects, which will be implemented primarily in the 2020s."

Under Uniper's strategy, the radiological demolition of the four reactors - during which all radioactive waste will be removed from each unit - will be carried out between 2020 and 2028. The total cost of decommissioning the Barsebäck and Oskarshamn units is estimated at SEK10.0 billion (USD1.1 billion).

"With Uniper's chosen strategy we can gather, coordinate and integrate the two projects," said Johan Svenningsson, chairman of Uniper Sweden. The basic idea is to take advantage of all the skills and experiences we have - not least from Germany where Uniper already completed the demolition of nuclear power plants."

"The Barsebäck plant has served Swedish society well with stable and fossil-free power generation," said Barsebäck Kraft AB CEO Åsa Carlson. "The chosen strategy is a boost for our organisation. Dismantling and demolition of closed reactors is one of the major industrial projects implemented in Sweden, where our project is to be coordinated with Sweden's radioactive waste management company's [SKB's] final disposal project and with other nuclear facilities."

The Oskarshamn plant is operated by OKG, in which Uniper owns a 54.5% stake in OKG, with the remainder held by Fortum. OKG strategy announced by Uniper. "With a coordinated dismantling and demolition we get coordination gains with the new strategy," said OKG CEO Johan Dasht. "We will be able to take advantage of Barsebäck's experience and use the same resources with specialist competence for the radiological demolition of Oskarshamn units 1 and 2."

OKG awarded GE Hitachi Nuclear Energy a contract in December 2016 to dismantle the reactor internals of units 1 and 2 at the Oskarshamn plant. The work includes dismantling, cutting and packing the reactor internals for final disposal. All the segmentation work is to be carried out underwater. The segmentation project is expected to be completed by the beginning of 2020.

The two ABB-designed boiling water reactors (BWRs) at Barsebäck, about 30 kilometers from Malmö in southern Sweden, shut down in November 1999 and May 2005, respectively. The two 600 MWe reactors - which began operating in 1975 and 1977 - were shut down early because of political pressure from neighbouring Denmark. All the nuclear fuel, which contained most of the radioactive substances, has already been removed from the Barsebäck plant. Reactor vessels and other major parts must be disassembled and transported away before the buildings themselves are dismantled. Work to dismantle, segment and package the reactor pressure vessel internals for final disposal is currently being undertaken by Westinghouse.

German utility EOn spun off of its non-renewable assets into Uniper in January 2016. EOn - the major shareholder in OKG - decided in October 2015 that Oskarshamn 1 and 2 would be shut down permanently. Unit 3 was unaffected by the decision. At that time it said unit 1 would close between 2017 and 2019, there would be no future investments at unit 2 and the reactor will not be restarted. In February 2017, OKG announced the decision to shut down Oskarshamn 1 in conjunction with a planned outage at the end of June last year. Oskarshamn 1, a 473 MWe BWR, started up in 1972, while Oskarshamn 2 is a 638 MWe BWR which began operating in 1974. Oskarshamn 3 is a 1400 MWe BWR which began operating in 1985.

OKG said it has not yet been decided what will happen to the land on which units 1 and 2 are located once they have been demolished. The company said it may even consider the construction of new nuclear units on the land or at least an extension to the operating life of unit 3.

"Oskarshamn 3 is an extremely important facility for the stability of the Swedish electricity system, and I do not exclude a lifetime extension in the future - if it is reasonable from a safety perspective and an economic perspective," Svenningsson said. "Through more fossil-free nuclear power in the Swedish electricity system, we can reduce fossil emissions in northern Europe."